Why> Apart
from HDAs, I can't think of any classic computer device that
Not EVERYTHING is a "classic computer device" :>
No, but everything discussed on this list should be :-)
can't be dismantled non-destructively. Mind
you, desoldering the HP9100B
I note that most of Votrax's products are troubling to dismantle
non-destructively (lots of potted "hide me so the user doesn't
know the secrets of my design" stuff).
Potting compounds can often be removed without imparing the functionality
of the device. I rememebr i obtained a thing called a 'Modem Maximiser',
back from the days of 1200 and 2400 baud modems. It connected betweem a
computer and a modem, added a real time clock, parallel port, mailbox,
etc. Quite a fun toy. Anyway, one of the options for this was an
encryption module, that was potted for security. I managed to cut away
the potting compount at least far enough to see the ICs it contained
(8031, 74xx373, OTP EPROM, all SMD packages), work out the
interconnections and dump the EPROM contetns. Worked fine afterwards too.
Also, any maritime equipment I designed was always
conformal
coated (several of those being "classic microcomputers" :> )
Confromal coating can be removed without ruining the device, surely?
Why? Can't
they be taken apart without damage?
It adds a level of stress and risk that I chose not to add.
My goal is to get a nice clean PCB that I can scan and then
convert to a photoplot. From there, I have tools that will
help automate reconstructing a schematic.
I have never found automatically-produced scheamtisc to be readable. I
prefer to do it by hand, checking each connection. The result is a
diagram I can actually follow...
-tony